In May 2012, he was appointed the Scottish Labour Spokesman for Sport. He held the role until July 2013, when he become Shadow Minister for Transport and Veterans. When Jim Murphy was elected Scottish Labour Party leader in December 2014, Mark was appointed as Shadow Minister for Learning, Science and Scotland's Languages, covering school education, qualifications, science, HM Inspectorate of Education, the Scottish Qualifications Authority and languages.

Upon his election at the age of 25, he became not only the youngest MSP of the 2011-2016 Scottish Parliament, but the youngest in its history.[3]

He sits on the Scottish Parliament's Education and Culture Committee and is a member of a number of Cross-Party Parliamentary Groups, including the Cross Party Groups on Deafness, Sport and Industrial Communities.

Through his work with the CPG on Deafness, he is in the process of putting a British Sign Language (BSL) (Scotland) Bill through Parliament. He became one of the first MSPs elected in 2011 to put forward plans for a Members Bill. The Bill was supported in principle by the Scottish Government in late 2014. [4]

Mark is a trained Mechanical Engineer and prior to his election to North Lanarkshire Council in 2008, he was a serving soldier in the British Territorial Army (TA).